Safety door interlocking switch



Feb. 27, 1923. 1,446,548

R. L. DE CAMP SAFETY DOOR INTERLOCKING SWITCH Original Filed Sept 25, 1917 2 sheets-sheet l Patented Feb. 27, 1923.

UNITED STATES PATENT OFFICE.

ROY L. DE CAMP, OF LOS ANGELES, CALIFORNIA, ASSIGNOR TO BAKER IRON WORKS, OF LOS ANGELES, CALIFORNIA, A CORPORATION OF CALIFORNIA.

SAFETY DOOR INTER/LOCKING SWITCH.

Original application filed September 25, 1.)1'7, Serial No. 193,188.

3, 1919. Serial No, 294,429.

To (ZZZ whom it may concern:

lle it known that T, Roy L. DE CAMP, a rn oi the United States. residing at Los the count oil Los Angeles and v tornia. have invented a new 'ttety Door Interlocking Switch c4? 1 the following is a specification.-

' vent-ion pertains to switches of the p ed to be operated by closing and V XUOCQIHBIHLS of a closure or other and an object of the invention is to a device of this character of minimum ab ity to become disorganized and one wl ch requires minimum attention to 5 maintain in operative condition.

Another object is to so construct the switch that the operating member thereof will interlock with a member mounted on a door. i v i Another object isto provide a construction in which the switch parts will not be subjected to blows or shocks when the door with which it isused is opened and closed.

This invention is a division of my Patent 26 Yo. 1356.698, dated October 26, 1920.

Other objects and advantages will appear in the subioined detailed description.

The accompanying drawings illustrate the invention Figure 1 is a fragmental rear elevation of a door structure with the newly invented switch applied thereto the door being shown :in, close position and the switch being closed,

Fin. 1" being shown in section.

Fin. the cover expose to view the internal mechanism of t the h. the switch being turned 90 ilOQlU from the position shown in .Flg.- and 1 witch being open.

an cie ation mainly in section on t. ed by zn*-a2. Fig. 8. I

r a plan section on line indicated I .[i 3 3.

The invention is designed to be connection with any suitable c osure. or other movable member. and is especially usein connection with elevator doors, an to door being indicated at 1 in Fig. 1.

is a plan View of Fig. 1.. the door 3 is a side elevation of the switch, and switch arm being omitted to used in' means such. "fol-instance, as screws 24:.

0: l is provided with a switch-open;

Divided and this application filed May rating arm 2 of suitable construction. The

.operatingarm 2 is so constructed as to engage a rotative switch member indicated in 5 general. by the character y In this instance, the member 3 is provided with teeth 4, 4- adapted to engage a tooth 5 of the arm 2. The arm 2 is attached by screws 6 or their equivalents to the door 1. The teeth 4, 4 project-from the hub 7 of the member 3. The hub 7 fits loosely on the outer projecting end ofa. stud 8 which is tightly inserted in an internal boss 9 of a switch case 10, there being a shoulder 11 on the stud 8 seated against the boss 9. The side of the case 10 opposite the boss 9 is formed by a removable cover 12 fastened in place by screws 13 01 equivalents and provided with a central orifice 14 to accommodate the inner end of the hub 7.

any suitable electric-insulating material, the

"drum -15 being kevedto. the hub .7 so as to be rotatedrby turning of the switch-operating; arm. In the instanceshown in the drawings the keyingof the drum 15 to the hub. 7 is accomplished bypins 16 projecting from the hub 7 into sockets'lr". formed in the drum 1511s clearly shown in Fig. 5. Thus when the switch-operating arm is turned the hub 7 and drum l5a1erotated on the stud S. A washer {1.8 is preferably interposedhetween the stud shoulder 11. and the drum 15 as shown in Figrz i and-the washer 19 is placed on. the outer end Of the stud 8 againstthe outer'face of the-huba7. The Washer 19 is held against outwarddisplacement by any suitable means, in the instance shown in the drawings said means comprising a cotter pin 90 inserted througha transverse hole 21 in the stud 8.

The drum 15 is provided on its curved 9 periphery with semi-circular contact members 23 mounted opposite to one another and itastenedtothe drum by any suitable The drum 1,5 is cut away at one side to form a flat face 25 along which extends a connector 22, 23, two of the screws 24 passing through the ends of the connector 26 to firmly hold it in place.

hen the drum 15 is turned sufficiently, the contacts 22, 23 are adapted to be engaged by other contact'mem bers 27, 28, each of which comprises a straight portion 29, an inwardly bent portion 30, and an end flange 31 engaged in a transverse groove 32 of an angular bracket There are two brackets and each is fastened by screws or equivalents 34, 35 to an insulating member 36 which in turn isfastened by screws or equivalents 37 to the caselO. The screws 35 project out sufiiciently .far beyond the inner face of the brackets 33 to form binding posts and on said binding posts are mounted washers 38 having semi-circular outturned flanges 39. Binding nuts 40 on the screws may be turned up to hold the leads, not shown, by which the switch is electricall v connected in the control circuit of the elevator .01. other circuit to be closed and opened by operation of the switch. Means are provided. to yieldingly hold the contacts 27, 28 with their curved portions 30 in engagement with the contacts 22, 23 when the drum is turned sufiiciently far for that purpose and such means are constructed as follows, though it is understood that they may be otherwise constructed if desired. The straight portion 29 of each contact member 27', 28 is provided with alperforation 41 to receive a headed pin 42 which projects through a perforation 43 inthe bracket 33, the head of the pin being at the outer face of the straight portion 29.. Each pin 42 is provided with washers 44 and coil springs 45 between the washers, said washers and springs being held in place by cotter pins 46 passing through holes'47 in the pins The expansive force of the springs 45 pulls the heads of the pins 42 against the contacts 27,28 so as to force the contact portions 30 towardthe drum 15 as is clearly understood.

It is now clear that when eitherof the contacts 22, 23 are in engagement with the contact 27 electric current will. flow between the binding posts 35.

From the foregoing it is clear that the switch is readily assembled and disassembled for. by removing the cotter, pin 20, the v."asher Q19, hub 7 and drum 15 may he slipped off of the stud 8, and by removing the cotter pins 46 the pins v 42 may be withdrawn from the perforations 41, 43 so as to release the contacts 27, 28.

The hub 7 is provided with an arm 49 which is adapted to engage a stop 50 on the case 10. when the switch is open, said stop being formed by an outwardly projecting lug of a strip 51that is fastened in place by one of the screws 13, or said stop may be otherwise constructed, if desired; Fastened to the arm 49 is a coil spring52- which sirable.

is connected with the case 10 by one of the screws 13. This spring 52 is so arranged as to tend to move the arm 49 into engagement with the stop 50 when the switch is closed.

In practical operation, assuming, for example, that the binding posts 35 are connected in a circuit controlling the operation of an elevator, it is clear that when the elevator door 1 is in the unclosed position the switch will. be in open position and thus break the electric circuit, and that in order for the operator to close the circuit so that he can operate the elevator car it will be necessary for him to close the door, as in Fig. 1, so as to move the switch-operating arm 2 sufficiently far to cause engagement of the contact 2'? with the contact 22.

As the arm 2 moves to the left in Fig. 1, it isclear that said arm interlocks. with the switch-operating member 4 by reasonv of the teeth 4, 4 engaging the teeth it is also clear that when the door 1 is moved to the left to open it the arm 2, because o 1. its interlocking with the switch-operatingincinber, will open the switch. Thus it is read ily seen that opening movement of the switch-operating arm, as well as closing movement thereof, is positively effected by movement of' the elevator door and not through the agency of any spring, weights, or by gravity. The spring52 merely holds the member 3 in such position that the tooth 5 will readily engage the tooth 4" when the door is moved from open to closed position.

The switch-operating member 3 may be turned to a position from that shown in Fig. 1 and for this purpose the drum 15 may be provided with sockets 48 correspondingwith and midway between the sockets 17 so that the pins 16 can be insertedin the sockets 48 by first withdrawing the hub 7 from the stud 8 and turning the hub 90 from the position shown in the drawings and then returning the hub in the turned position to insert'the pins 16 in thesockets 48. By this construction it is readily seen that the switch case may be placed above or beneath the closure. if such placing be de- The switch parts are shown in the drawings as being assembled in positions suitable for use with a door opening to the le ft from the inside of the elevator, but by turningthe switch case through an :mgle of 180, before fastening it in position. on the door casing, and fastening the arm 2 to the door so that the path of movement of the arm. will be in a plane above the switch member 3 the door may be arranged to open 1 to the right from the inside of the elevator. This will be clear by simply turning Fig. 1 upside down. I

- In operation, rotation of the drum causes wiping or rubbing engagement of the contacts 22 23, 27, 28 thus cleaning the contacts of any foreign matter inimical to closm of the electric circuit.

it is noted that cutting awa of the drum to form the flat face 25 produces an air gap between the contact portion 30 and the drum thus increasing the insulating of the contact portion 30 from the connector 26,

It is understood that the various parts above specifically described may be otherwise constructed within the spirit and scope of the appended claims.

1' claim:

1. In combination, a case an insulating member in the ease secured to the wall thereof, angular metal brackets having one leg secured by screws to the inner face of the insulating member, said screws projecting sutficiently beyond the inner face of the brackets to form binding posts, binding nuts on the screws, a drum of insulating material rotatably mounted in the case, means to turn the drum, electric contacts on the periphery of the drum, electric contacts having flanged ends engaging the other legs of the respective brackets, the last named contacts having inwardly bent portions adapted to engage the first contacts when the drum is turned, and means yieldingly holding the second contacts toward the drum.

2. In combination, a case having a removable cover, means to hold the cover in place, a stud projecting from the inner face of the case through the cover, a drum of insulation material rotatably mounted on the stud, electric contacts on the periphery of the drum, a hub rotatably mounted on the pro jecting portion of the stud and projecting through the cover and provided with pins detachably engaging the drum, means on the stud to prevent separation of the hub and drum, electric cont-acts mounted in the case and insulated therefrom, and means yieldingly holding the last contacts toward the drum.

Signed at Los Angeles, California, this 8th day of April, 1919.

ROY L. DE CAMP.

Vitnesses:

W. S. Hoao, L. M. EGINTON. 

